U.S. Pat. No 4,345,249 to S. Togashi describes a LCD display panel in which the electrodes of each display element of the LCD panel comprise a pair of intermeshed, or interdigitated, electrodes in substantially a single plane. U.S. Pat. No. 4,345,249 discloses a first comb-shaped electrode pattern, to which a display signal voltage is applied through a switching element, and a second comb-shaped electrode pattern which is held at a reference potential. The first and second comb-shaped patterns are mutually intermeshed and formed upon a single substrate of the panel, such that application of a display signal voltage causes an electric field to be produced in a direction substantially parallel to the substrate plane. Such a display has come to be referred to as an in-plane switched (IPS) LCD. This is in contrast to a conventional twisted nematic (TN) LCD, in which the electric field which acts upon the liquid crystal is produced in a direction normal to the substrate plane.
IPS LCDs typically have the advantage of much wider viewing angles than TN LCDs ( see M. Oh-e and K. Kondo, Appl. Phys. Lett. 67, 3895 (1995)) exhibiting less angle-dependent contrast and color variation. However, IPS displays typically have the disadvantage of slower switching times than conventional TN LCDs following the removal of the applied display signal voltage. These slower switching times have been one of the factors hindering the widespread adoption of IPS liquid crystal display panels despite the important advantage of much wider viewing angle.